Automatic feed-trip mechanism.



G. L.- LIBBY.

AUTOMATIC FEED TRIP MECHANISM.

6 SHEBTS-SHEET 1,

Patented Apr. 6, 1909.

APPLICATION FILED JUNE 29, 1903.

G. L. LIBBY.

AUTOMATIC FEED TRIP MEGHANISM.

APPLIUATION FILED JUNE 29, 1903. 917,320, Patented Apr. 6, 1.909.

s SHEETS-5335B C. L. LIBBY. AUTOMATIC rim-1n TRIP MECHANISM.

APPLIOATION FILED JUNE 29, 1903. 917,32. Patented Apr. 6, 1909. 6 SHBETSSHEET 3.

W V 7 r W 1-- Ii- 1: u H I A Ill! |||l Ll 1 J u Q H n H T i n WK Q. L. LIBBY.

AUTOMATIC FEED TRIP MECHANISM.

APPLICATION FILED JUNE 29, 1903.

Patented Apr. 6, 1909 6 SHEETSSHEBT 4.

G. L. LIBBY. AUTOMATIC FEED TRIP MECHANISM.

APPLICATION IEILED JUNE 29,1903.

917,320. Patented Apr. 6, 1909.

6 SHEETSSHEET 5.

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G. L. LIBBY.

AUTOMATIC FEED TRIP MECHANISM.

APPLICATION FILED JUNE 29, 1903. 91 7;,32Q. Patented Apr. 6, 1909. 6 SHBETSSHEET s.

TESSES mart; srnrns An FFICE CHARLES L. LIBBY, OF MADISON, WISCONSIN, ASSIGNOR TO GISHOLT MACHINE COMPANY, OF MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

AUTOMATIC FEED-TRIP MECHANISM.

Specification of Letters Patent.

Patented April 6, 1909.

Application filed June 29, 1903. Serial No. 163,623.

T 0 all whom it may concern: I 7

Be it known that I, CHARLES L. LIBBY, a citizen ofthe United States, residing at Madison, in thecounty of Dane and State ofWiS- .consin, have invented certain new and useful Improvements in Automatic- F-eed-Trip Mechanism, of which the following is a specification. M

My 'present invention pertains to automatic feed trip mechanism as applied to machines employing a cross-rail carrying crossheads, such for instance as vertical mills, planers, milling machinery, and the like.

The object of the invention is to'provid'e means for tripping off the feed at any prede termined point, whether the toolsare moving or working'in a vertical or ahorizontal direction.

The arrangement of the mechanism is such that it mayhe set 'so as to feed the requireddistance and then throw out automatically;

and, if desired, again set to feed a greater distance. The dials which are employed may also be used as a continuous scale for theex treme travel of the heads ineither direction, and by the use of four dials the heads may be moved in either direction any number of inches or fractions thereof to within one onethousandth of an inch. I

In the drawings: Figure 1 is a horizontal sectional view of the mechanism shown as applied to. a vertical mill cross-rail, the section being taken on the line 1.1 of Fig. 2; Fig. 2 a front elevation thereof; Fig. 3 a sectional view taken on the line 3-3 of Fig. 2; Fig.4 a transverse sectional view on theline 4-4, of Fig. 3; Fig. 5 an'elevation, portions being shown in section to more clearly illustrate certain features of construction; Fig. 6-

a sectional elevation of the clutch mechanism, the section being; taken on the hue 5'5 of 1; Fig. 7 a pers ective viewof one of the dial plates, viewer from the -rear, and

showing the cam carried thereby; Fig. S a perspective view of one of the disks which work in conjunction with the dials, said disk cariw'il a cam which I actuates the sto mechanism; Fig. 9 a front face view thereo Fig. 10 a detail of the clutch; Fig.- 11 2. perspective view of the rocker-shaft and arms;

12 a similar view of the with its attendant parts; Fig. 13 a perspece 14 a rear view of a modification of the invention, the stop mechanism being shown as apgears F, G.

. in mesh with a bevel-gear H, mounted upon setting lever rive view of one ofthe actuating}; rods; Fig.

plied to a planer; Fig. 15 a side elevation ofa portion of the same; Fig. 16 a sectional view of the clutch mechanism; and Fig. 17 an elevation of a ortion of amill shoeing my invention applied thereto.

Referring to the first construction illustrated, A denotes the case or feed bracket, A the cross-rail, and A the tool head (see Fig. The cross feed screw is denoted by B, and C indicates the feed rod.

D designates the actuating rod or shaft, to which motion is imparted in any suitable manner. Said rod has splined upon it a clutch member E, provided with teeth at its opposite ends which, when the clutch is shifted on the shaft, engage similar teeth formed on the outer face of each of then-bevel- Said gears are free to rotate upon the actuating shaft, and are constantly one end of a shaft I, a pinion J being secured to the o posite end of said shaft and meshing with a arge gear K. This gear occupiesa position intermediate the cross feed screw and the feed rod and meshes with pi-nions or 8 gears L, mounted on the feed rod and screw.v The outer ends of said last-named members are polygonal in form, and'the pinions L are slidably mount-ed'thereon, so that they must of necessity rotate with the rod and screw, but may still be moved out of mesh with the gear K, when desired. Each of the inions or gears L is provided with an extender sleeve or collar 0, in order to facilitate its manipulation.

ltlounted u on the feed rod C is a dial P, having suitab e graduations marked thereon, which are to be readin conjunction'with a zcro mark, shown in Fig. 2. Said rodalso carries a spiral gear Q, which meshes with a Pl18l gear R, mounted upon one end of a L haftS,a worm T being secured to the other end of said shaft. The worm T meshes with a worm gear U, carried by a shaft Y, the latter having at its outer end a large dial W. A disk X is securely fastened upon shaft Y in rear-of said dial, said disk being provided with a T-shaped channel or groove Y. A bolt or screw Z is seated in this channel, the threaded end thereof extending through the .05 dial and being provided with a thumb-nut, so that by manipulation bf the nut the dial and disk may be locked together when the parts have been brought into any desired relation.

Disk X carries a beveled stud or cam a, see

Figs. 5, 8 and 8, which under certain condiits inner end projecting into a groove or channel formed in the rod. A collar (1 is secured upon the rod adjacent to its rear end and serves to limit its inward movement. rear end of the rod bears. against the upper extremity or face of a rockcr-arn1 e, mounted upon one end of a rocker-shaft f. To the opposite end of the shaft is secured a second arm 6, which works in conjunction with it rod 1), similar in its construction to rod 1); in fact, the parts just described are duplicated for the feed screw and in order to save unnecessar repetition are not described in detail,simi a1" letters of reference being applied thereto, which. are rimed to avoid confusion.

Eachof the dia s W and WV is provided with a cam or lug M, which as will be hereinafter set forth acts as a trip-off for the mechanism when the zero-mark on the dial being used coincides with that on the fixed portion of the mechanism.

. A shaft. 9 is journaled in an extension h of the member A, said shaft carrying at its rear.

end a yoke t, with inwardly-proj ecting fingers 5i, whicn engage the clutch E and serve to actuate the same. The yoke is provided with an arm or finger is, the rounded end of which is in direct alinement with two spring-actuated plungers 1,1. Said plungers are so proportioned and arranged t rat when the clutch occupies 'its medial, inoperative position, each plunger will bear against the end of said finger; the plunger-actuating springs m being at such time under like stress, or under no stress, as the case may be, and the collars Z, 1 carried by the plungers bearing against the wall of the casing in which they worh, to

prevent overthrow of the parts.

, The forward end of shaft 9 is provided with a rectangular lug or blockn, which fits into a recess formed in one face of a lever 0, said lever being. pivoted to the block by a pin 1), which is passed through said parts. This lever is provided with a hollow pro ection gr (see Fig. 5) and a screw 1" is threaded into the block, passing freely through an o ening formed in the lever in line with the ollow projection; A spring 8 encircles the screw and, bearing on thereof and at its opposite end on the lever, serves to hold the same against the lug or block n.

Lever 0 is provided with a handle atone end, while at the opposite end 1t 1s formed with a lug twhich extends out in line w1th a lug or projection n formed upon. the extended portion 6 of the rocker-arm e.

Said

the under face of the head r In the operation of the machine the lug tis in engagement with one or anotherof the faces of lug it according to the direction of feed required. To determine the extent of contact or hearing between these two lugs a set-screw 'v is mounted in the lever 0 in line with lug n. By turning the screw inward, the lever will be shifted on its fulcrum and the extent of contact between the two lugs consequently lessened, thereby effecting a quick release of the lugs as soon as one or the other of the rocker-arms e, e is actuated. The adjustment of the lever in this manner enables the mechanism to be brought to a position of rest, with the dials in exact register with the zero-marks.

Springs w,'Figs. 2, 3 and 5, are attached to the rocker-arms e, e, and to a fixed portion of the bracket, and serve to hold said arms in contact with the rods 6, b, and also to hold lug t in contact with lug it until the rocker-arms are actuated by one or the other. of said rods.

The large dials W, W, may be graduated as desired, they being shown in'the drawings as graduated to one-fourth of an inch, while the small dials P, P, are shown as graduated to read to one one-thousandthof an inch,

Of course, these graduations may be modified to suitthe requirements of any particular machine, and will vary according to the pitch of the threads upon the feed screw and the'gears actuated bythe feed rod.

It is thought that the operation of the apparatus thus far set forth will be evident from the descriation given. Supposing, for instance, that t is feed rod C is to be brought into action, the slidable pinion L thereon will be shifted into position with relation to the large intermediate gear K, which as before stated is constantly in mesh with the inion J, mounted upon the shaft 1 The ever or handle 0 will then be shifted in one or the other direction so as to bring the clutch E into driving engagement with gear G, or F according to the direction of feed re quired, whereupon the motion of the shaft 1 D will be imparted through thc'gearing to the pinion L, and consequently the dials P and W will be rotated.

The movement of the lever 0 to shift the clutch will bring the lug a into contact with the outer face of lug t, as shown in Figs. 2

and The en agement of the parts will inches opposite 'zero on the bracket or stat onary part and toclamp the dial by means of the knurled nut on the bolt Z. As shown, the feed will be automatically released when the zero-marks on the dial and bracket coincide,*c am M actuating rod 1 and through the :OOIlIlBClJlOl'lS above described, releasing clutch E;

disk X. .lWhen this is accomplished a crank' isa plied to the-outer squared end of the feet rod'{or screw, as the case maybe, and by turning the crank motion isimparted tojthe c'l'oss he'a'd andtool, and through the con-. nectinggears to the dial (W or W) until the.

graduation "corresponding to 4% coincides wan the zero-mark n the bracket; Then, by setting the corresponding small dial,- P or P, to zerofandmanipulating the crank, a further rotation'equal to anadvance of one-- eighthor-I 125/1O0Q of an inch will be obtained, which amount may be easily readon the small dial. Thus the total movement of ig; inches of thegtool from a given point is It will, of

quickly-and accurately secured. course,',be understood that it is not essential to turn-the small dial back to the zero-mark whenadvance of the tool is ,to be efiected, as

the graduationsmay be read either forwardor backward; butfor the average operator and to insure absolute ace aoy, it is the better and saferpractice to return the dial The operation of the mechanism as applied to the feed rod and feed screw is, of course, the 'sarne,'an'd any desired length of feed may be secured.

As will be seen, it is possible after having set the dials-and fed a given amount, and as abohsequence having tripped the feed, to reset: the dials and feed-to the, same or any other amount. This operation can be repeatedindefinitely, or until the end of the travelis reached. This, of course, is very desirable in step work, such for instance as with cone-pulleys and the like. Taking, for exam le, 'a cone pulley of three steps, each. step. eing three inches wide, the feed dial canv be set for three inches for the first step,

then again at 3 for the second step, and so on, the urpose being that when the feed dial has been once adjusted for the proper distance of feed it will trip automatically instead of requiring to be watched by the operator. y

The cam a, carried by the disk X, acts as before noted to throw the feed at the extreme end of the travel of the cross-head or slide in order to avoid breakage whichzmight otherwise occur.

In Figs. 14, 15. and 16'another-embodiment of the invention is illustrated, the -mechanism being therein shown as applied to a planer. In these figures A denotes the usual reciprocating rack, which imparts motion to -a pinion B mounted uponha shaft which extends forwardly. and-roar ries 'a gear D which in turn connects directly with the ratchet gear or feed rods in the rail, these portions", however,. being omitted as they form no part of my present lnvention and are well'unders'tood. in order to. apply the stop mechanism, .the shaft G is, d vided and couplings E?, F are applied thereto, the coupling E being fixed. to one section of the shaft, while couplingF v may be shifted longitudinally upon the shaft to withdraw the teeth of the two members from engagement with one :another. A- spring G servesnormally to force the coupling mem bers apart. The coupling F is formed with an annular groove, into which extend-the fingers H- of a yoke 1 secured, to the operating-lever J jSaid operating-lever is'similar in all respects to the lever 0, heretofore described, and its inner end .WOlkS in conjunctionwith a locking'arm or member K This arrnis'mounted' upon a shaft L, to

which are attached arms M ,'l\'l which act in conjunction-with the releasing rods in the same manner as hereinbetore described in connection with the other form of the invention. The disks and the cams carriedthereby are similar to" those above set forth, and no further description thereof is deemed necessary.

'As will be seen upon reference to Fig. 2, the large dials are each provided with two series of graduations, so that they will correctly indicate the feed in either direction. These dials in operation makesoinewhat lessthan a complete revolution for the extreme travel of the cross head or slide, they being graduated in inches from Zero to the full amount of travel, or in any other desired manner.

It is obvious that many changes may be made in'the construction described without departing from the spirit of my invention and the broader claims made herein are, therefore, to be read with this fact in View.

I While two gears L'are illustrated in the drawings, in practice but one is provided for purpose of explanation and. a clear uncle-r standing of the mechanism.

Having thus described my invention what I claim isz 1. in coi'nbination-with a vertical mill or other machine/having a cross-rail;-a.head' carried thereby; feeding mechanism forsaid head adapted to be actuated mechanicallyor manually at will; an automatic feedrelease mechanism for throwing out the feed, said mechanism being located out of the path of travel of the head; and means for setting said throw-out mechanism at any point in the course of travel of the head, whereby the feed may be thrown out one or more times at any point or points between the extremes of travel of the head.

2. In combination with a vertical mill or other machine having a cross rail, a head carried thereby; suitable feed mechanism for said head; means for effecting a trip of the feed at any point or points intermediate the extremes of travel of the head and an automatic knock-off for tripping the feed, said knock-off being provided. with a cam which automatically and positively trips the feed mechanism at the extreme end of its travel, substantially as described.

3. In combination with a vertical mill or other machine having a cross rail, a head carried thereby; suitable feed mechanism for said head; a graduated dial; gearing intermediate said dial and feed mechanism, the gearing being so proportioned and arranged that the dial makes less than a complete revolution for the extreme travel of the head, whereby the operator may read directly from the dial the extent of travel-of the head;

and means controlled by the dial for rcleasing the feed mechanism.

4. In combination with a vertical mill or other machine having across rail, a head carried thereby; suitable feed .mechanism for said head; an adjustable graduated dial; a second adjustable graduated dial; gearing intermediate said dials to cause them to work in conjunction with each other; and a trip deviceffor the feed mechanism controlled by the dials, said dials being graduated so that they may be adjusted to effect the throwing out of the feed inecl'ianisin at a predetermined point, substantially as described.

5. In icombination with a vertical mill or other machine having a cross rail. a head carried thereby; suitable feed mechanism therefor; a graduated dial; a second graduated dial, a trip device for the feed mechanism, controlled by thedials, to throw off the feed at any desired point according to the adjustment of the dials; suitable connections intermediate said dials to operate them either separately or conjointly; and a lever for setting the feed muchanism, said lever being so arranged that the feed may be thrown in either direction or out altogether,

substantiallv as described.

6. In combination with a vertical null or other machine having a cross rail, a head carried thereby: suitable feed mechanism;

a graduated dial moving in unison with said head and thereby indicating the extent of travel of the same, substantially as described:

and a trip device for the feed mechanism controlled by thehlial.

7. In combination with a vertical mill'or other machine having a cross rail, a head carried thereby; a cross feed screw; a feed rod; an actuatingshaft; driving conneotioiis intermediate said shaft, cross feed screw and feed rod, whereby one or the other of said latter members may be placed in operative.

relation vi ith the actuating shaft; an adjustable trip mechanism for said connections operated by the rotation of the rod or screw,

v. hereby the feed v. ill be interrupted or stopped when the parts have been moved a predetermined distance; and means for determining the adjustment of the trip mechanism.

8. In combination with a vertical mill or other machine having a cross rail, a head carried thereby; a cross feed screw; a feed 'rod; an actuating shaft, connections intermediate said shaft, cross feed screw and feed rod for throwing one or the other of the latter members into operative relation with said actuating shaft; a trip mechanismfor said cross feed screw and feed rod; means for adjusting said trip mechanism to bring it into operation at any predetermined point ;'and means for determining the adjustment of the trip mechanism.

In combination \i' ith a vertical mill or other machine having across rail a head carried thereby; a cross feed screw; a feed rod; an actuating shaft; gearing intermediate said shaft, cross feed -scre'zv and' feed rod; feedtrippingmechanism actuated by said cross feed screw and feed rod; means for adjusting said tripping mechanism to bring it into operation at any desired point; and means for determining the adjustment of thetripping mechanism.

10. In combination with a vertical mill or other machine having a cross rail; a head carried thereby;-an actuating shaft; a feed rod; a cross feed screw; gearing actuated by said shaft for driving the feed rod or feed screw; means for positioning the gearing to throvv the same into operative relation v. ith the cross feed screw or feed rod as desired; a trip mechanism for the feed screw-i; a trip mechanism for the feed rod, said trip mechanisms oper-, ating upon the means for positioning the gearing and serving to release said means and the gears hen the parts-have traveled a predetermined distance; an d means for determining the positions of said trip mechanisms. 11. In combination v ith a vertical mill or other machine having a cross rail, ahead carried thereby; an actiiating'shaft; a cross feed screw; a feed rod; gearing interniediate'said cross feed screw, feed rod and actuating shaft; a lever for. controlling the position of said gearing to throw it into operative relation vJith either the cross feed screw of the feed rod; adjustable trip mechanisms for the cross" feed screw and-"feed rod actuated" di. 'rectlyby the rotation of said rdd and screw;

cameo.

said trip; mechanisms acting upon the clever toshlft it to its medial or normal position when the parts haverbeen moved a predetermined distance; and means for adjusting and indicatmg the positions of the trip mechanisms.

T2. .In combination with a vertical mill or other machine having a cross rail, a head car ried thereby; anactuating shaft across feed screw; a feedirodz' gearing. intermediate said screw, rod and actuatin shaft; a lever; means controlled by said ever for throwing the gearing into operative relation; adjustable trip mechanisms for thefeed screw and the feed rod, respectivel said trip mechanisms being driven direct by the movement of said screw or rod connections intermediate said trip mechanisms and the lever for.

throwing the lever to its 'medial or normal position when the parts have traveled a predetermined distance; and means for indi.

cating the adjustment of the trip mechanisms.

13. In combination with a vertical mill or other machine having a cross rail, a head carried thereby; an actuating shaft; a clutch mounted upon said actuatmg shaft; a cross feed screw; a feed rod; gearing-intermediate said cross feed screw, the feed rod and the clutch, said clutch being normally disconnected therefrom; a lever for positioning the clutch; trip mechanisms for the cross feed screw and the feed rod, respectively, said trip v mechanisms being driven from said screw and rod; connections intermediate the trip mach anisms and the lever for shifting the lever and releasing the clutchwhen the parts have moved a predetermined distance; and means for adjusting the trip mechanisms and indicating such adjustment.

14. Incombination with a vertical mill or other machine havmg 'a cross rail, ahead carried thereby an actuatingfshaft; a clutch carried by said shaft; a cross feed screw; a feed rod; gearing intermediate said screw, rod and clutch; a lever for moving said clutch into operative relation with the gearing; trip mechanisms for the screw and-the rod; respectively, said mechanisms being actuated directly by the movement of the screw or the rod; an vadjustable connection intermediate said trip mechanisms and the actuating lever; and means for setting the trip mechanw isms and indicating the extent of movement of'the head. v

"15. In combination with a verticalmill or other machine havingi-al'cross rail; a head carried thereby; an act iating shaft; a cross feed screw; a feedrod; a clutch mounted upon the actuating shaft; gearing intermediate said clutch'and the cross feed screw and feed.

rod; a lever for controlling the position of said clutch to throw it'into operative relation with the gearing; atri'p. mechanism for the-screw; a trip mechanism for the rod, said trip mechanisms being actuated directly by the rotationof the screw or rod; a connection common to both of said trip mechanisms and the lever, for releasing said lever when the parts have moved a predetermined distance; and means for adjusting the :trip mechanisms and indie-atin such adjustment.

, 16. In com ination with a vertical mill or other machine having a cross rail, a head carried thereby afeed rod or screw; an actuating the extent of feed which is to take place,

connections intermediate said dials for driving-them in a fixed relation, and means actuated by one of said dials'for releasing the gearing. j

' 17. In combination with a vertical mill or other machine having a cross rail, a head-carried thereby; a crossfeed screw or rod; an actuating shaft; gearing intermediate said shaft and the cross feed screw or rod; a'trip mechanism operated by the movement of said screw or rod, said trip mechanism comprising a graduated dial mounted upon and rotatable with said feed screw or rod, a second graduated dial, the graduations of which are coarser than those of the first dial, and driving connections intermediate said dials, said dials showing'the extent of feed which is to take place; and adjustable meanscarried by ried thereby; a cross feed screw or rod; an

actuating shaft; gearing intermediate said actuating shaft and the cross feed screwor rod; an operating lever for throwing said gearing into position to actuate the rod or screw in one or the other direction; and an automatic trip mechanism for releasing said lever, said trip mechanism comprising a graduated-dial carried by and revoluble with the feed screw or rod, a second graduated dial, the graduations of whicharecoarser than those of the first dial, said dials'indieating the extent of feed which is to take place, a shaft upon which said'second dial is mounted, shaft and the cross feed screwor rod for causing said shaft to operate as the screw or rod is turned, a disk carried by said shafts cam extending'out'wardly from saiddisk, means to clamp together said disk and the dial. mounted upon the chaft, a rod extend-- .ing into the path of thecam, and a locking connection for "thelever' iii linewith' the op posite end of the rod and adapted and ar,-

said second dial to bring the trip mechanism connections 7 intermediate said Cir ranged to be moved thereby to release the lever when the rod is moved endwise by the cam, substantially as described.

19. In combination with a vertical mill or carried thereby; an actuating shaft; a cross feed screw; a feed rod; a clutch. member carmediate said clutch and the cross feed screw and feed rod; a lever for controlling the position of the clutch; a rocker-shaft; rockerarms connected to said shaft; a locking arm or projection secured to the rocker-shaft and provided with a lug extending outwardly therefrom in line with a similar lug formed upon the lever; atrip .mechanism for the 5 cross feed screw; and a trip mechanism for j the feed rod said mechanisms each comprising a graduated dial carried by the screw or rod, a second graduated dial, the graduations of which are coarser than those of the first dial, a shaft upon which said dial is loosely mounted, driving connections intermediate said shaft and the cross feed screw or feed rod, a disk carried by said shaft, a cam extending outwardly from said disk, a rod having one end lying in the path of the cam while its opposite end is in contact with one of the rocker-arms, and means for holding said rocker-arm in contact with said rod.

20. In combination with a. vertical mill or 1 other machine having a cross rail a head carried thereby; a cross feed screw or rod; an actuating shaft; a clutch carried by and rotatable with said shaft; gearing intermediate said clutch and the cross feed screw or red; a shaft a rocker arm connected to said shaft and in operative relation with the clutch; a lever pivotally connected to the op osite end of said shaft 5 a rocker shaft; a ocking arm or member carried by-said shaft; means for adjusting the position of the lever sothat it will have a greater or less 5 bearing upon said locking arm; and a trip mechanism operated by the feed. screw or red when the parts have moved a predeteremcee 21. In combination with a vertical mill or other machine having a cross rail; a head carried thereby; a cross feed screw; afeed rod; an actuatingshaft; gearing actuated by other machine having a cross rail :1 head;

said shaft to drive the screw or rod; means j located at one end of the cross rail to throw v the gearing into operative relation with. the med by said actuating shaft;'-gearing inter-'5 mined distance, said mechanism serving to release the lever and to permit the clutch to move back torts normal position, substantially as described.

and indicating the position of the respective trip mechanisms.

22. In combination with a vertical mill or other machine having a cross rail; a head carried thereby; a feed rod; a feed screw; a graduated dial working in conjunction with the feed screw; a second graduated dial working in conjunction with the feed rod,

said dials moving in unison with the head according as the feed screw or feed rod is in operation and thereby indicating the extent wof. travel of the head; an actuator for the rod and screw; and 'a trip device carried by each of said dials for controlling the actuator and consequently the operation of the rod and screw.

23. In combination with a vertical mill or other machine having a cross rail; a head carried thereby; suitable feed mechanism for said head; a. graduated dial adjustable about its axis; gearing intermediate said dial and feed mechanism the gearing being so ro ortioned and arranged that the dial malies less than a complete revolution for the extreme travel of the head, whereby the operator may read directly from the dial the extent of travel of the head; and means controlled by the dial for releasing the feed mechanism.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHAR-LES L. LIBBY.

Witnesses HARR J. PARKE,

D. H. WRIGHT, Jr. 

